Nonlinear saturation of laser driven plasma beat wave by oscillating two-stream instability

Two copropagating lasers, having frequency difference Δω≈ωp, drive a plasma wave. The plasma beat wave amplitude increases with time initially due to the laser beams. As time grows, the plasma beat wave acquires large amplitude and it becomes susceptible to oscillating two-stream instability producing shorter wavelength Langmuir wave sidebands and a low frequency electrostatic mode. The decayed sidebands divert the energy of plasma beat wave by oscillating two-stream instability and saturate it.